Example 12 in Chapter 10 compared reaction times in a simulated driving test for the same students when they were using a cell phone and when they were not. The table shows data for the first four students. For all 32 students, 26 had faster reaction times when not using the cell phone and 6 had faster reaction times when using it.
a. Are the observations for the two treatments independent samples, or dependent samples? Explain.
b. Let p denote the population proportion who would have a faster reaction time when not using a cell phone. Estimate p based on this experiment.
c. Using all 32 observations, find the test statistic and the P-value for the sign test of H0: p = 1/2 against Ha: p > 1/2. Interpret.
d. What is the parametric method for comparing the scores? What is an advantage of it over the sign test?

Reaction times in cell phone study Using Cell Phone? Yes 636 623 615 672 Student No 604 556 540 Difference 32 67 75 150